A big event on 20 August 2025 at the Friesdorf bus depot of Bonn’s SWB (Stadtwerke Bonn Verkehrs GmbH): Daimler Buses was handing over ten Mercedes-Benz eCitaro buses to SWB (vehicles 2501 to 2510).
These are not SWB’s first battery-electric buses, as there are already four 12-metre vehicles from Ebusco and three articulated vehicles from Solaris. In addition, SWB previously had six 12-metre electric buses from the manufacturer Sileo in Salzgitter (vehicles 1501 to 1506), but these have already been removed from the fleet.
Until now, SWB has been rather hesitant to put battery buses into service. Now, however, ‘things are really taking off’. Five more eCitaro buses from Daimler Buses are scheduled to arrive in Bonn as early as next summer 2026, and SWB CEO Anja Wenmakers reported in her speech that a tender for six more electric buses is currently underway. It has not yet been decided who will supply these vehicles, and then there will be a very large order ‘in the pipeline’: Ms Wenmakers spoke of 35 vehicles.
The ten new eCitaro buses in detail
The new eCitaro buses from SWB are three-door models. SWB made the decision to only purchase three-door solo and four-door articulated vehicles three years ago. The first buses to comply with this are the 2022 models. According to SWB, the advantage of rapid passenger exchange at bus stops is too great when the bus has one more door.
The new electric buses with the numbers 2501 to 2510 are 12,135 mm long, 2,550 mm wide and 3,400 mm high. With this height, they cannot pass through the low railway underpass on Rheinallee, at least not at the edges of the road. ‘We are considering installing a traffic light system that only allows passage through the underpass in one direction at a time. Then the buses could drive in the middle of the road, where the underpass is high enough.’ (Until then, however, the Rheinallee underpass is off limits to electric buses – and also to the hydrogen buses of Regionalverkehr Köln.
The vehicles are powered by ZF’s ‘AxTrax AVE’ electric drive, which has a peak output of 250 kW and operates at a voltage of 400 volts. Mercedes installs the ‘ZF RL 82 EC’ with independent suspension as the front axle.
A special lever on the steering wheel allows the driver to activate the retarder as needed. This slows down the vehicle while simultaneously recovering energy (recuperation).
Safety is ensured by driver assistance systems such as Active Brake Assist (ABA), which detects difficult situations and intervenes by braking, and the turning assistant, which intervenes when people (pedestrians, cyclists) or objects are in the blind spot next to the bus when turning.
Although Bonn’s new eCitaros still have conventional rear-view mirrors, a surround camera system gives the driver a complete 360° view around the bus.
SWB claims a range of 290 kilometres for its new electric buses. This means that they can easily serve the vast majority of SWB’s daily routes. Only on routes that leave the depot very early and return very late could there be a shortage. And on the express bus line to the airport (Cologne/Bonn), where the buses travel more than 600 kilometres a day. This is not yet possible for electric buses – at least not for regular service buses.
The vehicles offer 31 seats and 51 standing places, meaning they can carry 82 passengers. In addition, a wheelchair (or pram) can be taken on board in the extra space by the middle door. A fold-out ramp at the middle door is now standard. The platform has four folding seats, two single seats on which passengers sit with their backs to the window, and a folding bench with two seats facing away from the direction of travel.
The permanently installed seats are of the ‘Mercedes-Benz City Star Function’ type. All vehicles are equipped with the ‘EvoThermatic basic’ air conditioning system, which is located on the roof of the vehicle. It works with a heat pump and an antiviral active filter. Its energy consumption has been reduced by an impressive 40% compared to previous air conditioning systems.
Twelve USB sockets allow passengers to use and charge their mobile devices.
To help visually impaired passengers find their way around the bus more easily, the handrails in the vehicle are bright yellow and have a ribbed surface.
The driver has a swivel seat with folding armrests and seat heating. The driver’s seat can be air-conditioned independently of the rest of the interior. And the driver is protected by a driver’s cab made of ESG safety glass that extends to the windscreen and has openings so that passengers and drivers can communicate with each other.
Video surveillance of the interior is now just as standard as a large monitor that provides information about the route and journey.
Daimler Buses also supplies the charging infrastructure
Daimler Buses not only supplied the buses, but also the turnkey charging infrastructure. The buses can be recharged via cable and CCS combo plugs as well as via pantograph. With the option of cable and CCS combo plugs, they correspond to what the existing SWB electric buses also need. The pantograph charging option is new for Bonn. In the version chosen in Bonn, the pantograph does not rise from the bus to the charging station, but descends from the station to the bus (‘panto down’). Years ago, the author heard from Hamburger Hochbahn that ‘panto down’ was safer.
Daimler Buses has supplied eight charging points for the ‘panto down’ system. The charging points are installed on masts, which are anchored in concrete bases. And since SWB is considering relocating its bus depot, the concrete bases have been designed so that they can be easily moved to the new location.
GO.Rheinland hands over funding approval for 3.4 million euros
The ‘GO-Rheinland’ association is the responsible approval authority for public transport in Bonn. Its deputy head of public transport funding, Christoph Nagel, handed over a funding cheque for 3.4 million euros. This amount will not only cover subsidies for the new buses, but also for the new charging infrastructure that has been installed at the Friesdorf depot.
Start of service of the new eCitaro buses
The new eCitaro buses are expected to enter service around 1 November. Before then, SWB wants to train its drivers on the vehicles and familiarise them thoroughly with the buses. The new electric buses will be used on lines 600, 605, 607, 631 and 633.
And diesel buses?
Will there be no more diesel buses for Bonn? Ms Wenmakers said: ‘We won’t be able to manage without purchasing diesel buses just yet. However, there will be no more brand-new vehicles. If we need diesel buses again, we will buy used ones.’ Just as ten used Citaro buses from 2019 have just been acquired from Vienna, which have been added to the fleet as vehicles 1902 to 1911.
However, one thing remains to be considered: if many transport companies switch to purchasing diesel buses that may be needed again in the form of used vehicles, the demand for used buses could increase significantly. This is likely to make used vehicles more expensive …
